Lymphotoxin beta receptor (LTβR) is a member of the tumor necrosis factor receptor (TNFR) family. The receptor is expressed on the surface of cells in the parenchyma and stroma of most lymphoid organs but is absent on T- and B-lymphocytes. Signaling through LTβR by the LTα/β heterotrimer (LT) is important during lymphoid development. LTβR is also known to bind the ligand LIGHT (homologous to lymphotoxins, exhibits inducible expression, and competes with herpes simplex virus glycoprotein D for HVEM, a receptor expressed by T lymphocytes), which has been implicated in T-cell driven events, both in the periphery and in the thymus. LT and LIGHT are expressed on the surface of activated lymphocytes. Blocking the LT pathway with a soluble decoy LTβR has been shown to be effective to treat autoimmune disease in various animal models.